Cured-in-place pipe repair (CIPP) has been used to repair damaged main sewer pipes or lateral sewer pipes as well as other types of conduits. Generally, a liner tube is impregnated with a resinous material, and is positioned in a pipe adjacent a damaged area of pipe. The liner tube is pressed against the wall of the damaged area of the pipe and the resin is allowed to cure in the bladder, thus leaving a renewed pipe wall. In addition, the liner tube is either pulled in place or inflated and inverted into the pipe to the damaged area in need of repair.
Liner tubes are generally formed from a flat piece of material, which is sized to be the correct length and width to fully cover the lateral pipe wall. The material is then rolled together, with the two ends of the width of the liner connected by stitching or welding, to form the tube. The diameter of the liner tube must be the same as the diameter of the lateral pipe. The same diameters are required so that there is a perfect fit of the liner tube in the lateral pipe. If the liner tube has a diameter less than the diameter of the lateral pipe, ripping or tearing of the liner could occur. If, on the other hand, the liner tube has a diameter greater than the diameter of the lateral pipe, the liner tube may fold over itself, or create bulges in the cured liner. These folds or bulges could cause blockages in the lateral pipe, and need to be cut or sanded out. The extra work is time consuming and expensive.
Methods of measuring lateral pipes do exist. For example, one method of measuring the diameter of a pipe involves inserting a rod directly into a lateral pipe to determine the diameter of the pipe. However, this method required direct access to the lateral pipe. The direct access may come from digging a large portion of the ground adjacent the lateral pipe and directly inserting the measuring device. However, digging to obtain direct access to a lateral pipe is time consuming and expensive. In addition, because a large excavation area must be dug to obtain direct access to the lateral pipe, the land around the pipe will remain unattractive until the landscaping of the site can be repaired. In other instances, such as where obstacles around the pipe exist, digging may not be possible to directly access the lateral pipe.
Accordingly, there is a need in the art for an improved method and means of determining the diameter of a lateral pipe without having to directly access the lateral pipe. There is also a need in the art for a method and means of determining the diameter of a lateral pipe to properly repair the wall of the pipe.